drivers/staging/gdm724x/gdm_tty.c

   1 /*
   2  * Copyright (c) 2012 GCT Semiconductor, Inc. All rights reserved.
   3  *
   4  * This software is licensed under the terms of the GNU General Public
   5  * License version 2, as published by the Free Software Foundation, and
   6  * may be copied, distributed, and modified under those terms.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15
  16 #include <linux/kernel.h>
  17 #include <linux/errno.h>
  18 #include <linux/tty.h>
  19 #include <linux/tty_driver.h>
  20 #include <linux/tty_flip.h>
  21 #include <linux/module.h>
  22 #include <linux/slab.h>
  23 #include <linux/usb/cdc.h>
  24 #include <linux/serial.h>
  25 #include "gdm_tty.h"
  26
  27 #define GDM_TTY_MAJOR 0
  28 #define GDM_TTY_MINOR 32
  29
  30 #define ACM_CTRL_DTR 0x01
  31 #define ACM_CTRL_RTS 0x02
  32 #define ACM_CTRL_DSR 0x02
  33 #define ACM_CTRL_RI  0x08
  34 #define ACM_CTRL_DCD 0x01
  35
  36 #define WRITE_SIZE 2048
  37
  38 #define MUX_TX_MAX_SIZE 2048
  39
  40 #define gdm_tty_send(n, d, l, i, c, b) (\
  41         n->tty_dev->send_func(n->tty_dev->priv_dev, d, l, i, c, b))
  42 #define gdm_tty_recv(n, c) (\
  43         n->tty_dev->recv_func(n->tty_dev->priv_dev, c))
  44 #define gdm_tty_send_control(n, r, v, d, l) (\
  45         n->tty_dev->send_control(n->tty_dev->priv_dev, r, v, d, l))
  46
  47 #define GDM_TTY_READY(gdm) (gdm && gdm->tty_dev && gdm->port.count)
  48
  49 static struct tty_driver *gdm_driver[TTY_MAX_COUNT];
  50 static struct gdm *gdm_table[TTY_MAX_COUNT][GDM_TTY_MINOR];
  51 static DEFINE_MUTEX(gdm_table_lock);
  52
  53 static char *DRIVER_STRING[TTY_MAX_COUNT] = {"GCTATC", "GCTDM"};
  54 static char *DEVICE_STRING[TTY_MAX_COUNT] = {"GCT-ATC", "GCT-DM"};
  55
  56 static void gdm_port_destruct(struct tty_port *port)
  57 {
  58         struct gdm *gdm = container_of(port, struct gdm, port);
  59
  60         mutex_lock(&gdm_table_lock);
  61         gdm_table[gdm->index][gdm->minor] = NULL;
  62         mutex_unlock(&gdm_table_lock);
  63
  64         kfree(gdm);
  65 }
  66
  67 static const struct tty_port_operations gdm_port_ops = {
  68         .destruct = gdm_port_destruct,
  69 };
  70
  71 static int gdm_tty_install(struct tty_driver *driver, struct tty_struct *tty)
  72 {
  73         struct gdm *gdm = NULL;
  74         int ret;
  75         int i;
  76         int j;
  77
  78         j = GDM_TTY_MINOR;
  79         for (i = 0; i < TTY_MAX_COUNT; i++) {
  80                 if (!strcmp(tty->driver->driver_name, DRIVER_STRING[i])) {
  81                         j = tty->index;
  82                         break;
  83                 }
  84         }
  85
  86         if (j == GDM_TTY_MINOR)
  87                 return -ENODEV;
  88
  89         mutex_lock(&gdm_table_lock);
  90         gdm = gdm_table[i][j];
  91         if (!gdm) {
  92                 mutex_unlock(&gdm_table_lock);
  93                 return -ENODEV;
  94         }
  95
  96         tty_port_get(&gdm->port);
  97
  98         ret = tty_standard_install(driver, tty);
  99         if (ret) {
 100                 tty_port_put(&gdm->port);
 101                 mutex_unlock(&gdm_table_lock);
 102                 return ret;
 103         }
 104
 105         tty->driver_data = gdm;
 106         mutex_unlock(&gdm_table_lock);
 107
 108         return 0;
 109 }
 110
 111 static int gdm_tty_open(struct tty_struct *tty, struct file *filp)
 112 {
 113         struct gdm *gdm = tty->driver_data;
 114
 115         return tty_port_open(&gdm->port, tty, filp);
 116 }
 117
 118 static void gdm_tty_cleanup(struct tty_struct *tty)
 119 {
 120         struct gdm *gdm = tty->driver_data;
 121
 122         tty_port_put(&gdm->port);
 123 }
 124
 125 static void gdm_tty_hangup(struct tty_struct *tty)
 126 {
 127         struct gdm *gdm = tty->driver_data;
 128
 129         tty_port_hangup(&gdm->port);
 130 }
 131
 132 static void gdm_tty_close(struct tty_struct *tty, struct file *filp)
 133 {
 134         struct gdm *gdm = tty->driver_data;
 135
 136         tty_port_close(&gdm->port, tty, filp);
 137 }
 138
 139 static int gdm_tty_recv_complete(void *data,
 140                                  int len,
 141                                  int index,
 142                                  struct tty_dev *tty_dev,
 143                                  int complete)
 144 {
 145         struct gdm *gdm = tty_dev->gdm[index];
 146
 147         if (!GDM_TTY_READY(gdm)) {
 148                 if (complete == RECV_PACKET_PROCESS_COMPLETE)
 149                         gdm_tty_recv(gdm, gdm_tty_recv_complete);
 150                 return TO_HOST_PORT_CLOSE;
 151         }
 152
 153         if (data && len) {
 154                 if (tty_buffer_request_room(&gdm->port, len) == len) {
 155                         tty_insert_flip_string(&gdm->port, data, len);
 156                         tty_flip_buffer_push(&gdm->port);
 157                 } else {
 158                         return TO_HOST_BUFFER_REQUEST_FAIL;
 159                 }
 160         }
 161
 162         if (complete == RECV_PACKET_PROCESS_COMPLETE)
 163                 gdm_tty_recv(gdm, gdm_tty_recv_complete);
 164
 165         return 0;
 166 }
 167
 168 static void gdm_tty_send_complete(void *arg)
 169 {
 170         struct gdm *gdm = arg;
 171
 172         if (!GDM_TTY_READY(gdm))
 173                 return;
 174
 175         tty_port_tty_wakeup(&gdm->port);
 176 }
 177
 178 static int gdm_tty_write(struct tty_struct *tty, const unsigned char *buf,
 179                          int len)
 180 {
 181         struct gdm *gdm = tty->driver_data;
 182         int remain = len;
 183         int sent_len = 0;
 184         int sending_len = 0;
 185
 186         if (!GDM_TTY_READY(gdm))
 187                 return -ENODEV;
 188
 189         if (!len)
 190                 return 0;
 191
 192         while (1) {
 193                 sending_len = min(MUX_TX_MAX_SIZE, remain);
 194                 gdm_tty_send(gdm,
 195                              (void *)(buf + sent_len),
 196                              sending_len,
 197                              gdm->index,
 198                              gdm_tty_send_complete,
 199                              gdm
 200                             );
 201                 sent_len += sending_len;
 202                 remain -= sending_len;
 203                 if (remain <= 0)
 204                         break;
 205         }
 206
 207         return len;
 208 }
 209
 210 static int gdm_tty_write_room(struct tty_struct *tty)
 211 {
 212         struct gdm *gdm = tty->driver_data;
 213
 214         if (!GDM_TTY_READY(gdm))
 215                 return -ENODEV;
 216
 217         return WRITE_SIZE;
 218 }
 219
 220 int register_lte_tty_device(struct tty_dev *tty_dev, struct device *device)
 221 {
 222         struct gdm *gdm;
 223         int i;
 224         int j;
 225
 226         for (i = 0; i < TTY_MAX_COUNT; i++) {
 227                 gdm = kmalloc(sizeof(*gdm), GFP_KERNEL);
 228                 if (!gdm)
 229                         return -ENOMEM;
 230
 231                 mutex_lock(&gdm_table_lock);
 232                 for (j = 0; j < GDM_TTY_MINOR; j++) {
 233                         if (!gdm_table[i][j])
 234                                 break;
 235                 }
 236
 237                 if (j == GDM_TTY_MINOR) {
 238                         kfree(gdm);
 239                         mutex_unlock(&gdm_table_lock);
 240                         return -EINVAL;
 241                 }
 242
 243                 gdm_table[i][j] = gdm;
 244                 mutex_unlock(&gdm_table_lock);
 245
 246                 tty_dev->gdm[i] = gdm;
 247                 tty_port_init(&gdm->port);
 248
 249                 gdm->port.ops = &gdm_port_ops;
 250                 gdm->index = i;
 251                 gdm->minor = j;
 252                 gdm->tty_dev = tty_dev;
 253
 254                 tty_port_register_device(&gdm->port, gdm_driver[i],
 255                                          gdm->minor, device);
 256         }
 257
 258         for (i = 0; i < MAX_ISSUE_NUM; i++)
 259                 gdm_tty_recv(gdm, gdm_tty_recv_complete);
 260
 261         return 0;
 262 }
 263
 264 void unregister_lte_tty_device(struct tty_dev *tty_dev)
 265 {
 266         struct gdm *gdm;
 267         struct tty_struct *tty;
 268         int i;
 269
 270         for (i = 0; i < TTY_MAX_COUNT; i++) {
 271                 gdm = tty_dev->gdm[i];
 272                 if (!gdm)
 273                         continue;
 274
 275                 mutex_lock(&gdm_table_lock);
 276                 gdm_table[gdm->index][gdm->minor] = NULL;
 277                 mutex_unlock(&gdm_table_lock);
 278
 279                 tty = tty_port_tty_get(&gdm->port);
 280                 if (tty) {
 281                         tty_vhangup(tty);
 282                         tty_kref_put(tty);
 283                 }
 284
 285                 tty_unregister_device(gdm_driver[i], gdm->minor);
 286                 tty_port_put(&gdm->port);
 287         }
 288 }
 289
 290 static const struct tty_operations gdm_tty_ops = {
 291         .install =      gdm_tty_install,
 292         .open =         gdm_tty_open,
 293         .close =        gdm_tty_close,
 294         .cleanup =      gdm_tty_cleanup,
 295         .hangup =       gdm_tty_hangup,
 296         .write =        gdm_tty_write,
 297         .write_room =   gdm_tty_write_room,
 298 };
 299
 300 int register_lte_tty_driver(void)
 301 {
 302         struct tty_driver *tty_driver;
 303         int i;
 304         int ret;
 305
 306         for (i = 0; i < TTY_MAX_COUNT; i++) {
 307                 tty_driver = alloc_tty_driver(GDM_TTY_MINOR);
 308                 if (!tty_driver)
 309                         return -ENOMEM;
 310
 311                 tty_driver->owner = THIS_MODULE;
 312                 tty_driver->driver_name = DRIVER_STRING[i];
 313                 tty_driver->name = DEVICE_STRING[i];
 314                 tty_driver->major = GDM_TTY_MAJOR;
 315                 tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
 316                 tty_driver->subtype = SERIAL_TYPE_NORMAL;
 317                 tty_driver->flags = TTY_DRIVER_REAL_RAW |
 318                                         TTY_DRIVER_DYNAMIC_DEV;
 319                 tty_driver->init_termios = tty_std_termios;
 320                 tty_driver->init_termios.c_cflag = B9600 | CS8 | HUPCL | CLOCAL;
 321                 tty_driver->init_termios.c_lflag = ISIG | ICANON | IEXTEN;
 322                 tty_set_operations(tty_driver, &gdm_tty_ops);
 323
 324                 ret = tty_register_driver(tty_driver);
 325                 if (ret) {
 326                         put_tty_driver(tty_driver);
 327                         return ret;
 328                 }
 329
 330                 gdm_driver[i] = tty_driver;
 331         }
 332
 333         return ret;
 334 }
 335
 336 void unregister_lte_tty_driver(void)
 337 {
 338         struct tty_driver *tty_driver;
 339         int i;
 340
 341         for (i = 0; i < TTY_MAX_COUNT; i++) {
 342                 tty_driver = gdm_driver[i];
 343                 if (tty_driver) {
 344                         tty_unregister_driver(tty_driver);
 345                         put_tty_driver(tty_driver);
 346                 }
 347         }
 348 }
 349